You can most certainly add controls on top of the ribbon, but not in the way you imagine them. For once, the ribbon control only allows buttons to be placed inside and not outside.
But if you place the ribbon in a relatively positioned container, then you can visually put on top other elements that also reside in the same container.
Of course, you have to take into consideration the number of tabs the ribbon may have and predicts the cases where the ribbon has so many tabs that they go below that other positioned container.
Please find attached a simplified page that demonstrates a scenario with couple controls for sample purposes. The container decorative border purpose is to show its position and dimensions.
Hope that this will be helpful.
the Telerik team
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